/*
* Copyright 2010 The Apache Software Foundation
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hbase.filter;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.util.Bytes;
import java.io.DataOutput;
import java.io.IOException;
import java.io.DataInput;
import java.util.List;
import java.util.ArrayList;
import com.google.common.base.Preconditions;
/**
* Pass results that have same row prefix.
*/
public class PrefixFilter extends FilterBase {
protected byte [] prefix = null;
protected boolean passedPrefix = false;
public PrefixFilter(final byte [] prefix) {
this.prefix = prefix;
}
public PrefixFilter() {
super();
}
public byte[] getPrefix() {
return prefix;
}
public boolean filterRowKey(byte[] buffer, int offset, int length) {
if (buffer == null || this.prefix == null)
return true;
if (length < prefix.length)
return true;
// if they are equal, return false => pass row
// else return true, filter row
// if we are passed the prefix, set flag
int cmp = Bytes.compareTo(buffer, offset, this.prefix.length, this.prefix, 0,
this.prefix.length);
if(cmp > 0) {
passedPrefix = true;
}
return cmp != 0;
}
public boolean filterAllRemaining() {
return passedPrefix;
}
public static Filter createFilterFromArguments(ArrayList<byte []> filterArguments) {
Preconditions.checkArgument(filterArguments.size() == 1,
"Expected 1 but got: %s", filterArguments.size());
byte [] prefix = ParseFilter.removeQuotesFromByteArray(filterArguments.get(0));
return new PrefixFilter(prefix);
}
public void write(DataOutput out) throws IOException {
Bytes.writeByteArray(out, this.prefix);
}
public void readFields(DataInput in) throws IOException {
this.prefix = Bytes.readByteArray(in);
}
}